Refrigerator

ABSTRACT

A refrigerator with a cooled inner chamber and a cooling circuit for a refrigerant, wherein the cooling circuit has a heat exchanger in the cooled inner chamber, a compressor for the refrigerant and a condenser on the outside of the refrigerator. According to the invention, a heat-storage material is in contact with the condenser.

The invention relates to a refrigerating device as claimed in the preamble to claim 1.

In order to cool the interior of a refrigerating device, a refrigeration circuit is usually provided in which a refrigerant circulates. The refrigeration circuit incorporates, on the outside of the refrigerating device, a condenser via which the heat absorbed inside the refrigerating device by the refrigerant is rejected to the ambient air. In order to be able to ensure the necessary heat exchange, the condenser must have a particular size which, especially in the case of built-in appliances, is at the expense of the size of the cooled interior.

The condenser must basically be designed such that the amount of heat that is produced during the operating time of the compressor can also be removed during the operating time of the compressor. During the idle times of the compressor, virtually no heat is produced. Consequently, at these times no heat transfer from the condenser to the ambient air is necessary either. The condenser must therefore be designed such that the amount of heat to be removed is rejected to the ambient air only at the times when the compressor is running.

It has also already been attempted, in the case of a smaller condenser, to increase the performance by means of a blower. Once again, however, as the blower must be activated during the operating time of the compressor, a noise level is produced that is perceived as annoying.

The object of the invention is to design a condenser such that its size can be reduced, thereby enabling the available space to be better utilized by enlarging the cooled interior.

This object is achieved according to the invention by a refrigerating device having the features set forth in claim 1. By means of the heat storage mass it is achieved that, during operation of the compressor, more heat can be extracted from the refrigerant than is dissipated to the ambient air by the condenser. This heat is temporarily stored in the heat storage mass. At the times when the compressor is not operating and normally no heat is being released to the ambient air by the condenser either, the heat previously absorbed by the heat storage mass is now released again. This means that heat is released by the condenser over a much longer period. The condenser can therefore be of smaller design and the available space better used.

In order to enable the heat absorbed in the heat storage mass to be dissipated more effectively to the ambient air, a device is provided which, in particular, makes the radiating surface larger. In a specific exemplary embodiment, a wide metal tape is placed in meander-shaped loops and the resulting loop assembly is connected to the heat store. The nature of the connection must be such that good heat transfer between the heat storage mass and the metal tape is guaranteed.

To increase the heat dissipation capacity still further, a blower can be additionally provided. Said blower should be disposed so as to boost the flow of air through the cavities of the loop assembly. This means that a large surface of the metal tape is swept by the air passed through and a large amount of heat is removed.

Advantageously, the running time of the blower is not limited to the running time of the compressor. As the temporarily stored heat can be dissipated even during the idle times of the compressor, it is advisable to operate the blower at these times also. The blower only needs to be turned off when the heat storage mass falls below a particular temperature and the compressor has not yet become active again. Should this threshold temperature of the heat storage mass not be attained, the blower is operated continuously. As the blower must not only dissipate the heat during the running time of the compressor, but also use the idle times of the compressor for heat dissipation, the blower need not have a very high output. A blower having the output required here does not produce a high sound intensity, nor does it therefore have a disturbing effect.

According to the invention, the heat storage mass has a liquid-filled container. Such a container is inexpensive to produce and shape so that it optimally utilizes the available space.

In order that the container is not required to be leak-proof, the liquid is accommodated in a plastic bag. Nor is the shape of the plastic bag critical, as the liquid-filled plastic bag complies very well to the shape of the container.

A liquid with high heat storage capacity should be used which, however, must not incur high costs. Water meets these requirements and is therefore best suited for this purpose.

Further details and advantages of the invention will emerge from the dependent claims in conjunction with the description of an exemplary embodiment which is explained in detail with reference to the accompanying drawings in which:

FIG. 1 schematically illustrates the refrigeration circuit of a refrigerating device,

FIG. 2 a shows an exploded view of the condenser of a refrigerating device according to the invention, and

FIG. 2 b shows the condenser from FIG. 2 a in the assembled state.

FIG. 1 schematically illustrates the refrigeration cycle of a refrigerating device. The refrigeration circuit comprises a compressor 1 and a condenser 9, which are located outside a cooled interior 6 of a refrigerating device, a throttling device 3 located at the edge of the cooled interior 6, and an evaporator 4 with a thermostat 5 which are located inside the cooled interior 6. Condensers, which dissipate the heat of a gaseous refrigerant (7) to the ambient air and in doing so condense the refrigerant, generally consist of serpentine coils of pipework. The refrigeration cycle takes place in a refrigerant-filled closed circuit. In the compressor 1, the gaseous refrigerant 7 is compressed and heated up by the compression process. In the condenser 9, heat is removed from the gaseous refrigerant 7 and rejected to the ambient air, the refrigerant being condensed in the process. The throttling device 3 upstream of the evaporator 4 ensures that a higher pressure obtains in the supplying than in the removing refrigeration circuit. This causes the liquid refrigerant 2 to be decompressed at the throttling device 3 and its aggregate state to change from liquid to gaseous, abruptly cooling it. The evaporator 4 therefore removes heat from the interior 6 and in doing so heats up the refrigerant 7. The gaseous refrigerant 7 passes to the compressor 1 and the cycle begins again. The amount of heat removed by the evaporator 4 is determined by the thermostat 5 which controls the on- and off-times of the compressor 1.

FIG. 2 a shows a new condenser with its serpentine coils 9 which are fixed to the outside of a container 8, a plastic bag 11 filled with a heat storage medium 10, a cooler 12 with cooling loops 13 and cavities 14, and a blower 15 with its nozzle 16. The container 8, shown as a rectangular box in this figure, can be adapted to suit the mounting requirements inside the refrigerating device and therefore varied in respect of its shape.

The serpentine condenser coils 9 run along the outside of the container 8 to which they are fixedly connected. The connection provides good heat transfer between the serpentine condenser coils 9 and the container 8. Likewise, the materials used for the container 8 and the serpentine condenser coils 9 have good thermal conductivity. The refrigerant is condensed in the serpentine condenser coils 9.

The plastic bag 11 filled with the liquid heat storage medium 10 is inserted in the container 8. The distinctive feature of this solution is that, because a plastic bag 11 is used, the container 8 is not required to be leak-proof. In fact, the hermetically sealed plastic bag 11 filled with the heat storage medium 10 is capable of assuming virtually any internal shape of the container 8 and of making large-area contact with the inside of the container 8.

Located on the top of the container 8 is the cooler 12 with its cooling loops 13. The cooler 12 is fixedly connected to the container 8 (see FIG. 2 b) and again consists of a material having good thermal conductivity. The type of cooler 12 shown here is a wide metal tape bent in a meander-shaped manner such that the individual cooler loops 13 are in contact with one another. Other designs are also possible, whether it be honeycomb or finned types.

The nozzle 16 is located on the pressure side of the blower 15, is flanged onto one of the end faces of the cooler 12 and covers the end face of the cooler 12 with its outlet surface. The blower 15 is preferably implemented as a radial or tangential blower in order, on the one hand, to minimize noise emission and, on the other, to produce an air flow that is as uniform as possible across the cooler 12. The design of said blower in itself is sufficient to eliminate a “dead spot” of the kind that can only be avoided with significant complexity when using axial blowers. The air flow is directed through cavities 14 formed by the cooler loops 13 and removes a large amount of heat.

The gaseous refrigerant 7 heated up by the compression process dissipates its heat to the highly thermo-conductive serpentine condenser coils 9. The condenser coils 9 in turn dissipate part of the heat to the ambient air, but another part to the container 8. As the container 8 likewise consists of a highly thermo-conductive material, it conducts the heat into the heat storage medium 10 contained in the plastic bag 11. Said plastic bag 11 and associated heat storage medium 10 is located in the internal space formed by the container 8 and has large-area contact with the container walls. The serpentine condenser coils 9 are dimensioned such that, during the running times of the compressor 1, they can dissipate the excess heat to the ambient air and to the heat storage medium 10.

In order to enable the heat stored in the heat storage medium 10 to be dissipated likewise as quickly as possible to the ambient air, a cooler 12 is provided on the top of the container 8. In the cavities 14 formed by the cooling loops 13 of the cooler 12, there is generated by means of the blower 15 a forced convection which is capable of removing a large amount of heat from the cooler 12.

Through the use of the heat storage medium 10 it is possible to temporarily store the heat produced by the compressor 1 and to dissipate this heat to the ambient air even during the idle times of the compressor 1. Ideally the blower is therefore operated during the running times but also during the idle times of the compressor. In this way heat dissipation takes place not only during the running time and it becomes possible to make the condenser much smaller than hitherto.

The heat storage medium 10 shall have a high thermal capacity, but must not incur high costs, so that the manufacturing costs of the condenser are not excessively increased. Water preeminently meets these requirements.

As the container 8 is not required to be leak-proof, no complicated manufacturing processes are required either. Thus it is always possible to adapt the container 8 to the mounting requirements in the refrigerating device. Less space is therefore required by the new condenser in each case than for the previous technical solutions.

As the blower 15 operates independently of the on-time of the compressor 1, it does not need to be particularly powerful. An inexpensive blower, which nevertheless operates very quietly, can therefore be used.

LIST OF REFERENCE SIGNS

-   1 Compressor -   2 Liquid refrigerant -   3 Throttling device -   4 Evaporator -   5 Thermostat -   6 Cooled interior -   7 Gaseous refrigerant -   8 Container -   9 Serpentine condenser coils -   10 Heat storage medium -   11 Plastic bag -   12 Cooler -   13 Cooler loops -   14 Cavity -   15 Blower -   16 Nozzle 

1-9. (canceled)
 10. A refrigerating device having a cooled interior and a refrigeration circuit for a refrigerant, wherein the refrigeration circuit includes a heat exchanger in the cooled interior, a compressor for the refrigerant, and a condenser outside the interior, the refrigerator comprising a heat storage mass in contact with the condenser.
 11. The refrigerating device according to claim 10 having a condenser provided on the outside of the refrigerating device and further comprising a heat dissipating device operatively associated with the heat storage mass for dissipating heat from the heat storage mass to the ambient air.
 12. The refrigerating device according to claim 11 wherein the heat dissipating device has a metal tape placed in serpentine loops.
 13. The refrigerating device according to claim 11 wherein the heat dissipating device includes a blower.
 14. The refrigerating device according to claim 13 wherein the blower is disposed so as to direct the flow of air through the loops of the metal tape.
 15. The refrigerating device according to claim 13 wherein the blower is configured for operation at certain times when the compressor is idle.
 16. The refrigerating device according to claim 11 wherein the heat storage mass includes a liquid-supporting container.
 17. The refrigerating device according to claim 16 wherein a plastic bag is provided in the container.
 18. The refrigerating device according to claim 16 wherein the liquid-supporting container contains water. 